Nonaqueous secondary battery

Abstract

A nonaqueous secondary battery comprising a cathode, an anode and a nonaqueous electrolyte disposed and sealed between the cathode and the anode wherein the anode is made of a carbon material as its active material, in which the carbon material comprises a fine core particle of a metal or an alloy thereof, and a carbon layer which is arranged and stacked in an onion-like shell configuration centering on the fine core particle, at least part of the carbon layer having a crystal structure in which graphite-like layers are stacked and the fine core particle having an average diameter of about 10 to 150 nm.

What is claimed is: 
     
       1. A nonaqueous secondary battery comprising a cathode, an anode and a nonaqueous electrolyte disposed and sealed between the cathode and the anode wherein the anode is made of a carbon material as its active material, in which the carbon material comprises fine core particle of a metal or an alloy thereof, and a carbon layer which is arranged and stacked in an onion-like shell configuration centering on each fine core particle,   at least part of the carbon layer having a crystal structure in which graphite-like layers are stacked and the fine core particles having an average diameter of about 10 to 150 nm.   
     
     
       2. A nonaqueous secondary battery according to claim 1 wherein the fine core particles comprises VIII element or an alloy thereof. 
     
     
       3. A nonaqueous secondary battery according to claim 2 wherein the VIII element is iron, nickel or cobalt. 
     
     
       4. A nonaqueous secondary battery according to claim 1 wherein the carbon material is formed of primary particles having an average diameter of about 40 to 200 nm. 
     
     
       5. A nonaqueous secondary battery according to claim 4 wherein the primary particles form a secondary body having a size of about 0.1 to 80 μm. 
     
     
       6. A nonaqueous secondary battery according to claim 1 wherein the crystal structure has about 0.336 to 0.360 nm as mean of interlayer spacing of (002) plane spacing determined by the X ray wide angle diffusion method, about 10 to 25 nm as mean crystallite size in the (002) plane direction and about 10 to 25 nm as mean crystallite size in the (110) plane direction. 
     
     
       7. A nonaqueous secondary battery according to claim wherein the content of the fine core particles in the carbon material is about 0.005 to 10 atm %.